TECHNICAL FIELD
[0001] The present invention relates to a receiver which detects a television broadcasting
system in effect where the vehicle is currently located and tuning automatically to
the detected system in order to ensure optimal status of reception at all times.
BACKGROUND ART
[0002] There exist a large number of television broadcasting systems, as listed in Fig.
1 showing television broadcasting systems corresponding to channel groups in Europe
and Fig. 2 showing television broadcasting systems matched with channels in European
countries. Different countries adopt different systems with specific channel frequencies
assigned to each nation.
[0003] Fig. 3 depicts schematically the typical format of a conventional television receiver
for use on board a vehicle in European countries. In Fig. 3, reference numeral 1 stands
for a television tuner, 2 for a reception antenna attached to the television tuner
1, 3 for a display connected to the television tuner 1, 4 for an audio unit connected
to the television tuner 1, and 5R and 5L for speakers.
[0004] The television tuner 1 comprises: a television tuner CPU 7 having broadcasting area
discriminating means 6 for selecting a specific broadcasting system from among many
systems; an operation unit 8 for manually operating the broadcasting area discriminating
means 6 from outside the television tuner 1; tuning means 9 for tuning to signals
received by the reception antenna on the basis of broadcasting system information
output by the television tuner CPU 7; and audio/video detecting means 10 for detecting
audio and video signals from an intermediate frequency (IF) signal output by the tuning
means 9. Television broadcasting systems A, B, ..., N to choose from by use of the
broadcasting area discriminating means 6 are stored beforehand in a memory 11.
[0005] The conventional television receiver in the above format works as follows: when television
reception is normal, television signals received by the reception antenna 2 are input
to the tuning means 9. On the basis of the broadcasting system information obtained,
the tuning means 9 tunes to a desired channel and outputs an appropriate intermediate
frequency signal. The IF signal is input to the audio/video detecting means 10 which
detects audio and video signals based on the broadcasting system information. The
video signal is fed to the display 3 for display. The audio signal is supplied to
the audio unit 4 which activates the speakers 5R and 5L for audio output.
[0006] However suppose that, as shown in Fig. 4, the vehicle travels from country A (B/G
system) through country B (B/G system) to country C (I system) in Europe. For the
transit from country A to country B, the broadcasting system remains unchanged and
there is no need to make additional settings on the television receiver. On the other
hand, the movement from country B to country C involves a change from one television
broadcasting system to another. A mismatch between the currently selected television
broadcasting system and the vehicle's present position requires manual operation of
the operation unit 8 to select a broadcasting system matching the vehicle's present
position via the broadcasting area discriminating means 6 and retrieve same from the
memory.
[0007] Conventional television broadcasting system detecting apparatuses of the above type
are such that the transit from country A to country B involves no change in the broadcasting
system with no need to make additional settings. However they involve the problem
that the transit from country B to country C requires tuning to a different broadcasting
system of the newly reached country. Switching the system from one broadcasting system
to another takes time and effort. Furthermore users need to have advance knowledge
of such television broadcasting systems.
[0008] It is therefore an object of the present invention to overcome the above-described
drawbacks and disadvantages of the prior art and to provide a receiver for use on
board a vehicle, the apparatus detecting the current position of the vehicle and checking,
based on the vehicle position signal as detected, whether the vehicle's present position
matches a currently selected broadcasting system. The apparatus further tuning automatically
to another system in case of a mismatch so that the newly selected broadcasting system
will match with the vehicle position.
DISCLOSURE OF THE INVENTION
[0009] In carrying out the invention and according to one system thereof, there is provided
a receiver for use on board a vehicle, comprising: a vehicle position detecting unit
for detecting a current position of the vehicle; a memory means remembering and coupling
a plurality of location information and the broadcasting systems that correspond to
the location information; broadcasting system selecting unit for selecting a broadcast
corresponding to the location information from the memory means and a receiver means
for receiving television transmissions based on the selected broadcast system.
[0010] The apparatus in the format outlined above allows a matching broadcasting system
to be selected automatically every time a mismatch occurs between the vehicle position
and the currently selected broadcasting system. Working as it does, the apparatus
ensures an optimum state of television reception without burdening the user with manual
operation.
[0011] The receiver of the present invention is adapted for use with TV broadcast systems
and can normally ensure optimal receiving conditions for the TV broadcasts.
[0012] The receiver of the present invention is adapted to couple a plurality of regional
information with the area information pertaining to each country and can automatically
ensure optimal receiving conditions with each area change.
[0013] In a preferred structure according to the invention, the receiver for use on board
a vehicle may utilize as its vehicle position detecting unit an onboard navigator
that receives global positioning satellite signals to determine where the vehicle
is currently located. The use of the navigator simplifies the format of the apparatus
and reduces its cost.
BRIEF DESCRIPTION OF DRAWINGS
[0014]
Fig. 1 is a table listing television broadcasting systems corresponding to channel
groups in Europe;
Fig. 2 is a table listing television broadcasting systems matched with channels in
European countries;
Fig. 3 is a schematic view showing a typical format of a conventional television receiver
for use on board a vehicle in Europe;
Fig. 4 is a sketched map of Europe showing area-wise television broadcasting systems;
Fig. 5 is a schematic block diagram of a television receiver incorporating a receiver
embodying the invention and for use on board a vehicle; and
Fig. 6 is a flow chart of steps showing how the apparatus works.
BEST MODE FOR CARRYING OUT THE INVENTION
[0015] The best mode for carrying out this invention will now be described in detail with
reference to the accompanying drawings.
First Embodiment
[0016] Fig. 5 is a schematic block diagram of a television receiver incorporating a receiver
practiced as a first embodiment of the invention. In Fig. 5, reference numeral 21
stands for a satellite that outputs a global positioning satellite (GPS) signal; 22
is for a navigator equipped with an antenna 23 for receiving the GPS signal and acting
as vehicle position detecting means; 24 is for a television tuner for admitting position
information from the navigator 22; 25 is for a reception antenna for receiving television
transmissions from an antenna 26 of a broadcasting station; 27 is for a display for
admitting and displaying an video signal from the television tuner 24; and 28 is for
an audio unit which admits an audio signal from the television tuner 24 and which
has speakers 29R and 29L for audio signal output.
[0017] The television tuner 24 comprises: a television tuner CPU 31 having broadcasting
area discriminating means 30 for selecting from a memory means 35 a broadcasting system
matching the current vehicle position based on the position information from the navigator
22 and coupling the preset plurality of location information with the broadcasting
system corresponding respectively to the location information; tuning means 32 for
tuning to a signal received by the antenna 23 on the basis of broadcasting system
information output from the television tuner CPU 31; and audio/video detecting means
33 for detecting audio and video signals from an intermediate frequency (IF) signal
output by the tuning means 32. Broadcasting systems A, B, ..., N, any one of which
is selected by the broadcasting area discriminating means 30, are stored beforehand
in a memory 34.
[0018] The first embodiment works as follows: Fig. 6 is a flow chart of steps showing how
the apparatus of Fig. 5 operates. When normal television reception is in effect (step
ST1), the television signal received by the reception antenna 25 is input to the tuning
means 32. The tuning means 32 tunes to an appropriate channel based on the broadcasting
system information acquired and outputs an IF signal accordingly. The IF signal is
input to the audio/video detecting means 33 which in turn detects audio and video
signals based on the broadcasting system information. The video signal is fed to the
display 27 for display, and the audio signal is supplied to the audio unit 28 for
audio output from the speakers 29R and 29L.
[0019] Meanwhile, the navigator 22 receives, via the antenna 23, the GPS signal from the
satellite 21 and detects the vehicle's current position based on the received signal.
As the vehicle changes position while receiving television transmissions, the apparatus
receives the current vehicle position from the navigator (step ST2). A check is made
to see if the currently selected broadcasting system matches the vehicle position
(step ST3). In the case of a match, the sequence returns to step ST1 and the process
is repeated. In case of a mismatch, the broadcasting area discriminating means 31
selects from the memory 34 another broadcasting system corresponding to the vehicle's
current position and switches automatically to the newly selected system (step ST4).
[0020] As described, the first embodiment selects and switches automatically to an optimal
broadcasting system every time the currently selected broadcasting system fails to
match the vehicle's detected position. This eliminates the need for manual switching
operations unlike the conventional apparatus. Furthermore it frees the user and television
broadcasts can be seen in a normally optimal state of reception.
[0021] Dedicated vehicle position detecting means may be included in the apparatus. Alternatively,
an existing onboard navigator may be used as the vehicle position detecting means.
The alternative setup will simplify the format of the apparatus and reduce its cost.
[0022] The accompanying figures list illustratively television broadcasting systems categorized
by country for search purposes. Alternatively, the broadcasting systems may be coded
by area. It is also possible for channel frequencies to be selected in the same manner
as described, i.e., on the basis of the vehicle's detected position.
[0023] Further, although embodiment 1 above was explained using a TV broadcast as a received
signal, it is possible to use a receiver receiving a radio broadcast or the like.
INDUSTRIAL APPLICABILITY
[0024] As described above, the receiver for use on board a vehicle automatically selects
and switches to a local broadcasting system of the geographical area that the traveling
vehicle has crossed into from another area where a different broadcasting system is
in effect. As such, the apparatus is adapted for use on board vehicles whose movement
crosses over areas of different broadcasting systems.
1. A receiver for use on board a vehicle, comprising:
vehicle position detecting means for detecting a current position of said vehicle;
a memory means for coupling a plurality of location information and broadcasting systems
corresponding respectively to the location information;
a broadcasting system selection means for selecting a broadcasting system corresponding
to the location information from said memory means based on the vehicle position information
as detected by said vehicle position detecting means; and
a receiving means which receives on the basis of the selected broadcasting system.
2. A receiver according to claim 1 wherein the broadcasting system is a TV broadcast
system.
3. A receiver according to claim 1 wherein the plurality of location information is regional
information with respect to each country.
4. A receiver for use on board a vehicle according to claim 1, wherein said vehicle position
detecting means is an onboard navigator receiving global positioning satellite signals.